3541 Analysis of the problems in the cold roll forming process of acoustic tubes - China Roll Forming Machine, Steel Water Tank Machine, Steel Silo Rollformer, Suppliers, Manufacturers, Factory - J&R
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Analysis of the problems in the cold roll forming process of acoustic tubes

2023-06-16
1. The generation of bag shaped waves is mainly due to the transverse tensile stress and transverse strain generated during the bending process of the plate, while the strain of the plate along the thickness direction is relatively small. According to the Poisson relationship of material deformation, shrinkage deformation will inevitably occur along the longitudinal direction in areas with concentrated deformation. In this experiment, this phenomenon mainly occurs at the four deformation corners, so the longitudinally contracted part applies compressive force to the middle plate, and some areas experience instability under the force, resulting in bag shaped bulges, which are commonly referred to as bag shaped waves. Bag shaped waves are mainly elastic deformation.
2. Edge waves (hereinafter referred to as edge waves) are a more common defect than pocket waves, and their generation is mainly a combination of two effects: the first is the same mechanism as the front pocket wave, which is due to the material in the curved section being subjected to transverse tensile stress, resulting in transverse tensile strain. When the strain in the thickness direction is not large, longitudinal shrinkage occurs according to the Poisson relationship, while the edge part is subjected to compressive stress, resulting in edge waves; The second type is that the material at the edge is first stretched and sheared to become longer under external forces, and then compressed and sheared again to produce plastic deformation and cause edge waves. These two effects overlap with each other, forming edge waves.
3. There are many reasons for longitudinal bending, one of which is that the edges of the section are subjected to tension when bending the side, attempting to elongate the entire section along the longitudinal direction. However, the tension is insufficient to elongate the entire rigid section, resulting in upward or downward bending at the front end of the rolled piece.